Poly-Urethane Lips

Polyurethane is a much more resilient material than fiberglass. Urethane has a much more pliable consistancy which is an important factor in the installation of the kit. The rigitity of fiberglass almost certainly requires adjustments and alterations to the material when fitting the kit, while urethane tends to be able to flex into place. Urethane can also withstand much more of an impact than fiberglass.